[tikhonj]

Haskell is non-standard and significantly different from everything else. Even if you ignore subjective qualities of the language, it takes some amount of initiative and self-selection to pick Haskell up at all, while lots of people are funneled into languages like Java, JavaScript, C#, Python by default. For example, relatively few universities (and presumably no bootcamps!) teach it at all, while it's hard to avoid programs that strongly feature Java and Python.

More generally, it makes sense for the sort of people who make non-mainstream choices to be qualitatively different from many who do go with the mainstream.